LYSIS AND RESORPTION OF CONCEPTUSES. 269 



would be something quite different from their resorption at the end of the gesta- 

 tion period in higher mammals, especially man. 



Although we have considerable evidence regarding retrogression and the 

 partial or even the total intrauterine absorption of conceptuses in various mammals, 

 I have not been able to find any conclusive evidence in the literature regarding 

 the occurrence of this phenomenon in man. It is true that cases of E. Fraenkel 

 (1903), Rosenkranz (1903), Polano (1904), and cases reported by others also are 

 referred to as such examples, but a careful examination of the reports shows that 

 those cases can hardly be regarded as falling under the head of intrauterine 

 absorption of ovum, embryo, or fetus. It is true that in the cases of Polano and 

 Rosenkranz, the skeletal elements only were seen to have been discharged, but 

 in the case of Polano the amniotic fluid nevertheless may have carried a great 

 many fragments of embryonic tissue away with it beforehand. Furthermore, 

 Polano did not claim his case as one of complete intrauterine absorption, but 

 merely as one of remarkable intrauterine maceration under aseptic conditions. 



The history of the case of Rosenkranz, on the other hand, shows quite clearly 

 that the fetus was destroyed by putrefactive changes. Rosenkranz himself em- 

 phasized this, but strangely enough ruled out entirely the occurrence of macera- 

 tion. He further stated that the patient herself noticed the discharge of some 

 bones with the "menstrual" flow. However, under the above conditions the 

 recurrence of true menstruation is exceedingly unlikely unless the fetus was dead 

 a considerable period before the rupture of the membranes occurred, and the 

 placenta had been detached at least partly, for only under such circumstances 

 could some regeneration of the mucosa occur and thus make a return to true 

 menstruation possible. It is nevertheless possible, however, that the time of 

 abortion was coincident with the date on which menstruation might have recurred. 

 A small number of cases in the Carnegie Collection have a history which makes 

 such a suggestion probable. Just why the expulsion of a dead, retained conceptus 

 should occur at the time when menstruation would have recurred normally had 

 pregnancy not supervened it is difficult to say, but since the inhibitory effect 

 upon the menstrual cycle exercised, directly or indirectly, by the living fetus is 

 absent in cases of premature death and retention, it is possible that the abortion 

 might occur at a time when the impulses of a return to the normal non-pregnant 

 status of the maternal organism becomes more evident; that is, at the time of the 

 recurrence of the normal menstrual cycle. 



One can not but recall in this connection another group of cases which give a 

 history of uninterrupted menstruation throughout the entire period of pregnancy. 

 In some of these cases it is evident that it is a question of more or less regular 

 hemorrhage rather than of true menstruation, and it may be possible that in the 

 others these hemorrhages happened to fall at intervals of the same length as the 

 normal intermenstrual periods. In the last group the exact status of the cases 

 can not be discerned from the histories alone. However, since there is no en- 

 dometrium, or at most a partial one, to shed, genuine menstruation manifestly 

 can not occur throughout pregnancy. Indeed, it seems more probable that the 



